The present invention relates to a device for measuring the transverse dimension of a thread by means of optoelectronical thread scanning means and thereto connected signal evaluation circuitry.
The term "thread" as used hereinafter generally encompasses thread-like and endless structures of textile or other kinds of structures, such as, for instance, monofilaments, yarns, glass fibers, wires and the like.
In U.S. Pat. No. 4,294,545 there are described a method and a device for continuously measuring the transverse dimension of a travelling thread-like structure by means of an array of optoelectrical sensors. By scanning the signal condition of the array in successive cycles there are produced serial digital scanning signals. By this particular measure there is eliminated the ground signal and the effect thereon of irregular contamination of the optical measuring area in which the thread travels. The ground signal is the scanning signal existing when there is no thread present in the measuring area.